------------[ cut here ]------------
!err
WARNING: fs/ext4/inode.c:2512 at mpage_map_one_extent fs/ext4/inode.c:2512 [inline], CPU#1: kworker/u8:15/1182
WARNING: fs/ext4/inode.c:2512 at mpage_map_and_submit_extent fs/ext4/inode.c:2601 [inline], CPU#1: kworker/u8:15/1182
WARNING: fs/ext4/inode.c:2512 at ext4_do_writepages+0x33b6/0x44b0 fs/ext4/inode.c:3077, CPU#1: kworker/u8:15/1182
Modules linked in:
CPU: 1 UID: 0 PID: 1182 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: writeback wb_workfn (flush-7:1)
RIP: 0010:mpage_map_one_extent fs/ext4/inode.c:2512 [inline]
RIP: 0010:mpage_map_and_submit_extent fs/ext4/inode.c:2601 [inline]
RIP: 0010:ext4_do_writepages+0x33b6/0x44b0 fs/ext4/inode.c:3077
Code: 0f 0b 90 e9 b6 d9 ff ff e8 47 d4 38 ff 90 0f 0b 90 e9 e6 dc ff ff e8 39 d4 38 ff 90 0f 0b 90 e9 94 df ff ff e8 2b d4 38 ff 90 <0f> 0b 90 bb ea ff ff ff e9 ae f8 ff ff e8 18 d4 38 ff 48 8d 3d 91
RSP: 0018:ffffc900069a6ce0 EFLAGS: 00010293
RAX: ffffffff828f0265 RBX: 0000000000000000 RCX: ffff88802a521f40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900069a70f0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100547d481 R12: ffffc900069a71a0
R13: dffffc0000000000 R14: 0000000000000001 R15: 1ffff1100547d496
FS:  0000000000000000(0000) GS:ffff88812482f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f80dac7c000 CR3: 000000002b4e0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ext4_writepages+0x1fe/0x4e0 fs/ext4/inode.c:3171
 do_writepages+0x338/0x560 mm/page-writeback.c:2560
 __writeback_single_inode+0x136/0x1230 fs/fs-writeback.c:1800
 writeback_sb_inodes+0x9db/0x1aa0 fs/fs-writeback.c:2111
 wb_writeback+0x41c/0xad0 fs/fs-writeback.c:2296
 wb_do_writeback fs/fs-writeback.c:2464 [inline]
 wb_workfn+0x437/0x10f0 fs/fs-writeback.c:2509
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>